Long before Big Pharma, people used a variety of natural remedies to ease digestive woes. Now that modern medicines are available to treat everything from indigestion to constipation, however, many people still prefer to seek relief from natural products that have stood the test of time. But do they work, and are they safe?
Here is the lowdown on a few of the ones I regularly encounter:
• Aloe Vera: commonly used to treat constipation
Aloe supplements come in two forms: capsules and juice. They typically contain one of two compounds – aloe latex or aloe gel. Aloe latex is extracted from underneath the skin of the aloe leaf. Its active ingredient – aloin – is a stimulant that may increase contractions in the colon. It also decreases reabsorption of water in the colon, leading to softer, more easily passed stools.
[Read: Digestive Enzymes: Help or Hype?]
Aloe gel is taken from the inner part of the aloe leaf and is generally less effective than latex as a laxative. Bottled aloe juice typically contains Aloe gel. Capsules may be formulated with crushed whole aloe leaves, which contain both latex and gel, or with the gel only.
There are multiple safety and efficacy concerns related to regular aloe vera supplementation, particularly of latex-containing products. For starters, once people begin taking aloe supplements regularly, they tend to develop a tolerance, requiring increased doses to maintain the effect. As the dose increases, safety is of increasing concern: case reports of fatalities and severe kidney dysfunction have been reported with high doses (1 gram per day) of aloe latex.
Aloe latex was once sold as an over-the-counter laxative medication but was banned by the U.S. Food and Drug Administration in 2002 because of these safety concerns; however, the ingredient remains in circulation when sold as a dietary supplement. Products derived from crushed whole aloe leaf will contain some latex naturally; other products that list aloe "inner leaf" as an ingredient will also have it.
[Read: 5 Common Causes of Belly Bloat.]
Aloe gel appears to be safe. Aloe can also interact with several types of medications – including certain diuretics, heart drugs, steroids and oral hypoglycemic agents for diabetes – causing dangerous electrolyte imbalances or hypoglycemia. Ingesting aloe as a laxative during pregnancy is of particular concern as it may cause birth defects or be toxic to the fetus.
Bottom line: It may work for a period of time, but it's not recommended for long-term use since the risks seem to outweigh the benefits. There are several safer natural laxatives out there. (Prunes, anyone?)
• Licorice Root: commonly used to treat heartburn and stomach ulcers.
Licorice root contains multiple compounds thought to benefit digestive ailments. In test tubes, licorice-derived compounds have been shown to inhibit the activity of Helicobacter pylori, a species of bacteria linked to gastric ulcers and gastritis (inflammation of the stomach lining); whether this effect would occur in the human body remains to be established. An active compound in licorice called glycyrrhizic acid that – in addition to its utility as a Scrabble word when you run out of vowels – may help ulcers heal by increasing mucous cell secretion and cell growth.
Glycyrrhizic acid, however, has a potentially dangerous side effect. It can severely alter blood pressure and potassium levels – particularly with prolonged use of high doses. As a safety precaution, many licorice supplements contain "deglycyrrhizinated" ("or deglycerized") licorice – abbreviated as DGL. Unfortunately, human studies generally have not supported a benefit of deglycerized licorice in helping gastric ulcers heal more quickly. Note that many "licorice" products are actually made with anise oil, which smells and tastes like licorice but doesn't contain the real thing.
Bottom line: It may help calm mild cases of gastritis but isn't likely to help heal an ulcer. Choose deglycyrrhizinated (deglycerized) licorice products only, and check with your doctor if you use any other medications to prevent harmful interactions. Pregnant women should avoid all forms of it because of a possible increased risk of pre-term labor.
• Peppermint: commonly used to treat abdominal pain in irritable bowel syndrome (IBS)
Peppermint oil contains menthol, a smooth muscle relaxant that can also desensitize pain receptors in the gut when used regularly. Used supplementally in the form of capsules or herbal tea, peppermint oil has been shown to relieve stomach pain, flatulence and mild gastrointestinal spasms. These spasms are often responsible for IBS symptoms like urgent, frequent bowel movements and borborygmi – gurgling or rumbling sensations in the bowels.
A review of 16 clinical trials found that enteric-coated peppermint oil capsules were significantly more effective in treating IBS symptoms or abdominal pain compared to a placebo. Peppermint oil was also found to be equally effective as certain anticholinergic drugs – prescription medications that inhibit smooth muscle contraction.
Since peppermint oil relaxes smooth muscle along the entire length of the digestive tract, however, it may worsen reflux in people with gastroesophageal reflux disease (GERD) – or in pregnant women prone to heartburn. This is because it relaxes the opening between the stomach and esophagus, giving excess stomach acid the opportunity to creep into the esophagus. Inexplicably, several brands of over-the-counter antacids for heartburn are offered in mint flavor; I advise my patients to avoid these!
Bottom line: It works! But avoid it if you are prone to heartburn.
• Activated Charcoal: commonly used to treat stinky gas
Activated charcoal is regular charcoal that has been specially treated to bind to organic molecules of all kinds – including smelly, sulfur-containing ones, thereby neutralizing their odor. For oral use, activated charcoal is sold as capsules, a powder or in biscuits. Activated charcoal is often used in external devices like briefs, pads, seat cushions and filters placed on colostomy bags.
In theory, ingesting activated charcoal might also reduce these odors in the colon before gas even leaves the body. But evidence of activated charcoal's effectiveness has been mixed, and studies have generally been too small to be generalizable. A study conducted on British dogs showed that activated charcoal supplements significantly reduced episodes of flatulence with "bad or unbearable odor" (I'm not making this up), though it's unclear whether these findings can be extrapolated to American dogs – or humans, for that matter.
Despite its promise as Febreeze for flatulence, activated charcoal is not without its adverse effects. For one, it can be incredibly constipating, which is why many products are formulated with sorbitol, a sugar alcohol with laxative effects. Secondly, activated charcoal binds to all organic molecules – including those in medications you may be taking – inhibiting their absorption. Therefore, it's important to dose medications – particularly thyroid medications – and active charcoal supplements several hours apart.
Bottom line: It may minimize the odor of foul-smelling intestinal gas, but it won't reduce the amount of gas you produce. Use with caution if you're prone to constipation or take other medications.
Michelle Truong-Leikauf, a dietetic intern and master's degree candidate at Columbia University Teacher's College in New York City, contributed to this article.
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Tamara Duker Freuman, MS, RD, CDN, is a NYC-based registered dietitian whose clinical practice specializes in digestive disorders, Celiac Disease, and food intolerances. Her personal blog, www.tamaraduker.com, focuses on healthy eating and gluten-free living.